(a) Field of the Invention
The present invention relates to LED lamp technology and more particularly to a heat sink module and an omnidirectional LED lamp holder assembly using the heat sink module.
(b) Description of the Prior Art
For the advantage of low power consumption, LED lamps have been gradually used to substitute for conventional tungsten lamp bulbs. However, LED performance largely depends on the ambient temperature of the operating environment. During the operation of a LED lamp, waste heat must be quickly dissipated. Conventional LED lamps commonly have the LED chips arranged at the front side to emit light forward. With this arrangement, the light intensity at the border area may be weak. With continuing development of lighting technology, LED lamps capable of emitting light in different directions are created. However, because a large number of LED chips are used in a LED lamp, the temperature inside the lamp rises quickly with the operation of the LED lamp, and the LED chips can easily be damaged by heat. Thus, the heat dissipation problem is serious.
A conventional LED lamp capable of emitting light in different directions is known comprises a rectangular heat-transfer prism and a plurality of radiation fins radially arranged around one end of the rectangular heat-transfer prism. The other end of the rectangular heat-transfer prism is a heat absorbing end shaped like a rectangular table. LED chips are mounted at the end face and side faces of the heat absorbing end of the rectangular heat-transfer prism for emitting light in different directions. However, the rectangular heat-transfer prism is a solid prism that cannot dissipate heat rapidly and does not allow arrangement of wires therein. Further, the cost of the rectangular heat-transfer prism is high. The mounting arrangement between the radiation fins and the rectangular heat-transfer prism is not stable.
There is known another conventional LED lamp design, which comprises a heat-transfer base block, a heat-transfer component connected to the heat-transfer base block and providing multiple mounting faces at different angles, a plurality of radiation fins radially arranged around the heat-transfer base block, and a plurality of LED chips arranged on the mounting faces of the heat-transfer component. According to this design, as the heat-transfer base block and the heat-transfer component are two separate members fastened together, waste heat cannot be fully and rapidly transferred by the heat-transfer component from the LED chips to the heat-transfer base block, and the heat dissipation efficiency is low. Further, this design complicates the fabrication.
There is known still another conventional LED lamp design, which uses a heat sink made by a stretch forming technique. This design of heat sink cannot effectively match the radiation fins for heat dissipation. Further, the wall thickness of the heat sink cannot be freely adjusted to fit the power of the LED chips to be used. Thus, materials of different wall thicknesses should be prepared to fit different application requirements, thus complicating the fabrication and increasing the cost.